An image forming apparatus utilizing an electrophotographic process includes a plurality of image forming units for respective colors (black, yellow, cyan, and magenta). On the surface of a photosensitive drum in the image forming units each include, an electrostatic latent image is formed and developed into a toner image for visualization. Such an image forming unit includes a static eliminator for eliminating static electricity and an electrostatic latent image that remain redundantly on the surface of the photosensitive drum. The static eliminator performs static elimination by irradiating the surface of the photosensitive drum with light.
In view of environmental friendliness, amorphous silicon, which is excellent in abrasion resistance and durable under long-term use, is used generally in the photosensitive drum. Amorphous silicon has a surface having a molecular structure that is apt to adsorb moisture. As a result, moisture is liable to be adsorbed into the surface of the photosensitive drum. When moisture is adsorbed into the surface of the photosensitive drum, the surface resistance of the photosensitive drum may decrease, thereby reducing the surface potential at an edge of the electrostatic latent image. As a result, image quality may degrade.
In view of the foregoing, it has been proposed to provide in the vicinity of the photosensitive drum, a substrate on which a heating element that heats the surface of the photosensitive drum is mounted (e.g., Patent Literature 1). In an image forming apparatus recited in Patent Literature 1, a light emitting element that eliminates static electricity on the photosensitive drum is mounted on one of main surfaces of the substrate while the heating element that heats the photosensitive drum is mounted on the other main surface of the substrate.